Hybrid bluegrass named &#39;dalbg 1201&#39;

ABSTRACT

‘DALBG 1201’ is an F1 hybrid bluegrass with exceptional turfgrass quality, dark green color, high shoot density, medium-fine leaf texture, and ability to persist under a range of environmental stresses typically encountered in the southern United States.

Latin name of the genus and species of the plant claimed: Poaarachnifera Torr.x P. pratensis L.F₁ hybrid.

Variety denomination: ‘DALBG 1201’.

BACKGROUND OF THE INVENTION

The Poa genus includes approximately 200 to 300 species, both annual andperennial types, that are native to temperate regions of northern andsouthern hemispheres. Of these, Kentucky bluegrass (Poa pratensis L.) isthe predominant perennial species of Poa used in the United States forturf and forage applications. Although it displays excellent turfgrassquality, its use in southern climates is limited because of itssensitivity to heat and drought stress. Texas bluegrass is well knownfor its heat and drought tolerance and is native to the southern regionof the United States spanning from New Mexico to South Carolina. Thefirst successful attempt to genetically improve stress tolerance inKentucky bluegrass was made in 1908 by George Oliver (Vinall and Hein,1937) by hybridizing Kentucky bluegrass with Texas bluegrass (P.arachnifera Torr.); however, it was not until 1998, 90 years later, thatthe first commercially available interspecific hybrid between Texasbluegrass and Kentucky bluegrass, ‘Reveille’, was developed (Read etal., 1999; PVP Certificate No. 9800337). This large span of time can beattributed to the limited amount of knowledge available for the twospecies as it pertains to their morphological and agronomiccharacteristics, as well as the complexity of their geneticcompositions.

Members of the genus Poa exhibit different ploidy levels, diploid,polyploid, or aneuploid, with a basic chromosome number of x=7. There isgreat variation in chromosome number both within and among species ofPoa (Patterson et al., 2005). Kentucky bluegrass is documented to havechromosome numbers ranging from 2n=24 to 124 (Love and Love, 1975), andTexas bluegrass chromosome numbers range from 2x=42 to 91 (Hartung,1946; Kindiger et al., 2011).

Even though greater success in hybridization may be achieved when highpolyploid parents such as Kentucky bluegrass are used as pollinators(Pepin and Funk, 1974), extreme differences in ploidy levels is stillone of the greatest barriers to successful interspecific hybridizationin Poa (Kelley et al., 2009).

Kentucky bluegrass primarily produces seed asexually through apomixis,although it does produce sexual seed at a low frequency (Grazi et al.,1961; Han, 1969, Wieners et al., 2006), and is referred to as afacultative apomict. ‘Reveille’ has been shown to produce 90% of itsseed apomictically (Read et al., 1999). In contrast to Kentuckybluegrass, Texas bluegrass is a sexually obligate dioecious species withseparate female and male plants present in the breeding population.Since the release of ‘Reveille’, other hybrid bluegrass cultivars withspecific improvements in heat and drought tolerance, and diseaseresistance, have been developed, including ‘Bandera’ (Smith et al.,2008) and ‘Thermal Blue’ (also known as ‘HB129’; U.S. Plant Pat. No.18,467).

SUMMARY OF THE INVENTION

The present disclosure relates to a new and distinct interspecific Poaarachnifera Torr. x P. pratensis L. F₁ hybrid variety named ‘DALBG1201’. ‘DALBG 1201’, formerly tested as TAES 5653 and 01-59-5, wasproduced in 2001 near Dallas, Tex. by fan-mediated bag crossing betweenTexas bluegrass ecotype 20-11 (3-88) (PI 655088) (unpatented) as thefemale parent and Kentucky bluegrass ecotype CS#4 (unpatented) as themale parent (pollen). ‘DALBG 1201’ represents a single genotype from afamily of 16 progeny. ‘DALBG 1201’ was first asexually propagated inDallas, Tex. by propagating vegetative material into smaller plugs andallowing the plugs to grow before splitting them again.

‘DALBG 1201’ is an experimental Texas bluegrass x Kentucky bluegrassinterspecific hybrids developed at the Texas A&M AgriLife Research andExtension Center in Dallas, Tex., which was evaluated over a 3-yearperiod (2010-2012) alongside 46 other experimental Texas bluegrass xKentucky bluegrass interspecific hybrids; five Texas bluegrass ecotypes(TAES 5679, 5681-5684); six Kentucky bluegrass genotypes (H8G-J86,PTDF-22-B-2, H86-712, TAES 5701, 5706, and 5709); two commercial hybridbluegrass checks (‘Reveille’, ‘Thermal Blue Blaze’); and ‘Rebel Exeda’tall fescue. The evaluations took place in multiple locations with testsites located in Auburn, Ala.; Dallas, Tex.; Starkville, Miss.; Raleigh,N.C.; and Knoxville, Tenn.

The turfgrass quality for DALBG 1201 was statistically superior to‘Reveille’ and ‘Thermal Blue Blaze’ in four test locations (Auburn,Ala., Starkville, Miss., Raleigh, N.C., Dallas, Tex.), and was in thesame statistical group in Knoxville, Tenn. (Table 3). The turfgrassquality of DALBG 1201 was statistically similar to ‘Rebel Exeda’ atAuburn, Starkville, and Knoxville and was superior in Dallas. Whenaveraged across all locations, the turfgrass quality of DALBG 1201 wasstatistically superior than the commercial checks ‘Thermal Blue Blaze’,‘Reveille’, and ‘Rebel Exeda’. ‘DALBG 1201’ differs from its parents andall other known Poa arachnifera Torr. x P. pratensis L. F₁ hybridcultivars.

The following are the most outstanding and distinguishingcharacteristics of ‘DALBG 1201’: It exhibits a combination of (1)exceptional turfgrass quality, (2) dark green color, (3) high shootdensity, (4) medium-fine leaf texture, (5) drawf canopy, and (6) theability to persist under a range of environmental stresses typicallyencountered in the southern United States. ‘DALBG 1201’ turf can also bedistinguished at least based upon its above-acceptable turfgrass qualityand reduced leaf-elongation rate under full-sun as well as in moderatelyand heavily shaded environments.

‘DALBG 1201’ turf can be distinguished from Texas bluegrass ecotype20-11 (3-88) turf (female parent) at least based upon their floretcharacteristics. Specifically, ecotype 20-11 (3-88) only has femalereproductive organs in its florets; while DALBG 1201 has a perfectflower with both male and female reproductive organs in its florets.Additionally, DALBG 1201 has finer leaf-texture, darker green cover, anddwarf canopy as compared to its female parent 20-11 (3-88). ‘DALBG 1201’turf can be distinguished from Kentucky bluegrass ecotype CS#4 turf(male parent) at least based upon the thioredoxin-like nuclear genemolecular marker.

BRIEF DESCRIPTION OF THE DRAWINGS

‘DALBG 1201’ is illustrated by the accompanying photographs, which showthe turfgrass quality analysis of ‘DALBG 1201’ as well as the claimedplant's vegetative and floral characteristics. The colors shown are astrue as can be reasonably obtained by conventional photographicprocedures.

FIG. 1—Shows the Genotype x Environment Stability Analysis of DALBG 1201and the three commercial checks ‘Rebel Exeda’, ‘Reveille’, and ‘ThermalBlue Blaze’ for (a) turfgrass quality, (b) shoot density, (c) seasonalcolor, and (d) leaf texture.

FIG. 2—Shows the leaf width differences between ‘DALBG 1201’,‘Reveille’, and ‘Rebel Exeda’.

FIG. 3—Shows ‘DALBG 1201’s lack of auricles and shows ‘DALBG 1201’ has amembranous ligule at the base of each leaf

FIG. 4—Shows a comparison of the inflorescence height and densitybetween ‘DALBG 1201’ (left), ‘Reveille’ (middle), and ‘Rebel Exeda’(right) photographed on Apr. 7, 2021 after 5 months of no trimming.‘DALBG 1201’ exhibited fewer inflorescences on average (9) compared to‘Reveille’ (26) and ‘Rebel Exeda’ (49)

FIG. 5—Shows the ascending culm node coloration of ‘DALBG 1201’,‘Reveille’, and ‘Rebel Exeda’ tall fescue.

FIG. 6—Shows the immature inflorescence shape and color of ‘DALBG 1201’panicle with exerted stigmas and anthers.

FIG. 7—Shows the mature panicle length and coloration of ‘DALBG 1201’,‘Reville’, and ‘Rebel Exeda’.

FIG. 8—Shows the anthocyanin present at the tips of maturing ‘DALBG1201’ inflorescence on Mar. 26, 2020.

FIG. 9—Shows a microscopic image of ‘DALBG 1201’ spikelet florets,anthers, stigmas, and glumes.

FIG. 10—Shows the immature ovary of ‘DALBG 1201’ and the attachedstigmas and mature anthers

DETAILED BOTANICAL DESCRIPTION

The following detailed description sets forth the distinctivecharacteristics of ‘DALBG 1201’. The claimed plant was four months oldwhen the data was collected in Dallas, Tex. Color references are to theMunsell Color Chart; 1977 Edition of the Munsell Color Charts for PlantTissues, unless otherwise indicated. Color designations provided referto both mature and immature stages unless otherwise indicated. If anyMunsell color designations below differ from the accompanyingphotographs, the Munsell color designations are accurate.

-   Plant:    -   -   Growth habit.—Semi-erect.        -   Natural plant height (at maturity).—34.8 cm.        -   Plant height before stem elongation.—17.8 cm.        -   Tillers on the culm.—None.        -   Self-fertility.—Female sterile.-   Rhizomes:    -   -   1^(st) internode length.—11.74 mm.        -   2^(nd) internode length.—15.76 mm.        -   3^(rd) internode length.—13.77 mm.        -   4^(th) internode length.—12.11 mm.        -   4^(th) internode diameter.—0.58 mm.        -   4^(th) node diameter.—1.04 mm.-   Leaves:    -   -   Length (flag leaf).—2.4 cm.        -   Width (flag leaf).—2.26 mm.        -   Leaf curling.—None.        -   Leaf sheath pubescence.—Absent.        -   Leaf sheath hairs on surface.—Absent.        -   Leaf sheath hairs on margin.—Absent.        -   Leaf sheath margin roughness (to touch).—Smooth.        -   Leaf sheath surface roughness (to touch).—Smooth.        -   Leaf sheath hairs just beneath leaf blade (under            collar).—Absent.        -   Leaf sheath color.—Green; Munsell color 2.5G value of 5 and            chroma of 5.        -   Leaf collar color.—Munsell color 5 GY color of 7 and chroma            of 6.        -   Anthocyanin coloration of the basal leaf sheath.—Absent.        -   Lower surface leaf coloration.—Munsell color 2.5G value of 4            chroma of 6.        -   Upper surface leaf coloration.—Munsell color 2.5G value of 3            chroma of 4.        -   Auricles.—Absent.        -   Ligules.—Present, membranous.        -   Ligule hairs.—Absent.        -   Keel.—Absent.        -   Leaf blade venation pattern.—Parallel.        -   Leaf blade color.—Very dark green Munsell color 2.5G value            of 3 chroma of 4.        -   Leaf blade color (winter).—Very dark green; Munsell color            2.5G value of 3 chroma of 4.        -   Leaf blade hairs (upper side).—Absent.        -   Leaf blade hairs (lower side).—Absent.        -   Stem color.—Munsell color 7.5 GY value of 7 chroma of 6.        -   Ascending culm internode length.—13.4 cm.        -   Culm node pubescence.—Absent.        -   Time of flowering.—Mar. 17, 2021 in Dallas, Tex.        -   Glumes length.—4.42 mm.        -   Lemma colors.—7.5 GY value of 6 chroma of 8.        -   Palea colors.—7.5 GY value of 6 chroma of 8.        -   Ligule color.—White/clear.-   Inflorescence:    -   -   Type.—Panicle.        -   Collar of the rachis.—Munsell color 7.5GY value of 7 chroma            of 6.        -   Panicle description (habit; type).—Upright; Compact.        -   Panicle length.—10.8 cm.        -   Panicle diameter.—2.4 cm.        -   Color.—7.5 GY value of 5 chroma of 4 with anthocyanin            present at tips with a coloration of 5R and a value of 1 and            chroma of 10.        -   Stigma length.—        -   Stigma color.—White.        -   Peduncle length.—5.8 cm.        -   Pedicel length.—5.07 mm.        -   Pedicel color.—Munsell color of 7.5GY value of 7 chroma of            5.        -   Awns.—Absent.        -   Culm diameter.—0.62 mm.        -   Number of panicle bearing tillers in the culm.—Average of 9            from 3 replications.        -   Culm color.—Munsell color 2.5G value of 5 chroma of 4.        -   Culm anthocyanin coloration of the nodes and            internodes.—Anthocyanin at the nodes appears very            infrequently compared to Reveille and is less intense with a            shorter gradation and coloration close to 5R with a value of            4 and chroma of 2.        -   Caryopsis shape.—Sterile with no seed development.        -   Florets per spike.—3.9 on average.-   Environmental resistance:    -   -   Cold (injury).—Moderately Resistant.        -   Heat.—Moderately Resistant.        -   Drought.—Moderately Resistant.        -   Low fertility.—Moderately Resistant.        -   Alkalinity (pH>7.5).—Highly Resistant.-   Disease resistance:    -   -   Leaf Rust (P. poae-nemoralis).—Moderately Resistant.-   Morphological analysis of ‘DALBG 1201’: Morphological comparisons    were made between ‘DALBG 1201’, ‘Reveille’, and ‘Rebel Exeda’ tall    fescue (Table 1 and 2). A 10.2 cm plug of each cultivar was    propagated into three 8-inch azalea pots filled with potting soil on    Nov. 16, 2020. Pots were buried in a sandbed in a randomized    complete block design on Dec. 11, 2020 to induce vernalization. Pots    were removed from the sand bed on Feb. 24, 2021 and placed in a 77°    F.±5° F. greenhouse. Supplemental lighting was provided with LED    lights to extend daylengths to 16 hrs. The first inflorescences    began emerging on March 15^(th) (Reveille), March 17^(th) (DALBG    1201), and March 22^(nd) (Rebel Exeda). Four sample measurements    were collected from each replicate pot for a total of 12 samples per    trait. Blade leaf length (cm) and width (mm) were measured from the    first fully expanded leaves before stem elongation. Plant height    before stem elongation (cm) was measured from the four tallest    leaves. Rhizome internode lengths (mm) were only measured on those    with new shoots between the first, second, third, fourth, and fifth    nodes. Rhizome diameters (mm) were measured on the fourth internode    and node. The ascending culm internode length (cm) was measured    between the nodes of the first and second leaves of the four tallest    inflorescences. Culm diameter (mm) measured the thickness of    ascending culm. Inflorescence length or plant height were measured    at full maturity from the base of the plant to tip of the    inflorescence. Flag leaf length (cm) and width (mm) were measured    from the four tallest inflorescences in each pot. Peduncle    length (cm) was measured between the flag leaf node and base of the    inflorescence. Panicle diameter (cm) and length (cm) were measured    from the four tallest inflorescences. Pedicel length (mm) was    measured between the node of the second branching spikelet and base    of the first floret. Glume length (mm) was measured between the base    of a lower glume and tip of an upper glume. The number of florets    per spikelet were counted randomly from one spikelet from each of    four inflorescences. The number of inflorescences were counted for    each pot and averaged.-   Vegetative characteristics: ‘DALBG 1201’ is similar in leaf blade    length to Rebel Exeda which is longer than Reveille (Table 1). The    leaf blade width of ‘DALBG 1201’ is intermediate to ‘Reveille’ and    ‘Rebel Exeda’ (Table 1 and FIG. 2). ‘DALBG 1201’ lacks leaf blade    hairs and auricles and has a membranous ligule at the base of each    leaf (FIG. 3). Natural plant height before stem elongation is    similar to ‘Reveille’ which is taller than ‘Rebel Exeda’ (Table 1).    Rhizome internode lengths of ‘DALBG 1201’ are not statistically    different from ‘Reveille’, but the fourth internode and node    diameters are larger than ‘Reveille’ (Table 1).-   Floral characteristics: ‘DALBG 1201’ inflorescences began emerging a    few days later than ‘Reveille’ and one week earlier than ‘Rebel    Exeda’. The ascending culm internode length is similar to ‘Reveille’    and longer than ‘Rebel Exeda’ (Table 2). No differences were    determined for culm diameter between the three cultivars (Table 2).    The mature plant height of DALBG 1201 after anthesis is more dwarf    compared to ‘Reveille’ and ‘Rebel Exeda’ (Table 2 and FIG. 4) and    ‘DALBG 1201’ exhibited fewer inflorescences on average (9) compared    to ‘Reveille’ (26) and ‘Rebel Exeda’ (49). Flag leaf length and    width of ‘DALBG 1201’ and ‘Reveille’ were similar and shorter and    narrower than Rebel Exeda (Table 2). The peduncle length of ‘DALBG    1201’ is very short compared to the other two cultivars (Table 2).    Compared to ‘Reveille’, ‘DALBG 1201’ has a shorter gradation of    anythocyanin present at the ascending culm node and occurs    infrequently compared to ‘Reveille’ which has a strong purple    coloration on every culm (FIG. 5). Although ‘DALBG 1201’ has a wider    panicle diameter than ‘Reveille’ and ‘Rebel Exeda’, the panicle    length is statistically similar to ‘Reveille’ and shorter than    ‘Rebel Exeda’ (Table 2). Although immature inflorescences of ‘DALBG    1201’ express no anthocyanin early after emergence (FIG. 6) it    appears at the tips of florets before maturity similar to ‘Reveille’    (FIGS. 7 and 8). No differences in number of florets per spikelet    were determined (Table 2). Glume length is statistically shorter for    ‘DALBG 1201’ compared to ‘Reveille’ and ‘Rebel Exeda’ (Table 2 and    FIGS. 9 and 10). Although anthers and stigmas are exerted in ‘DALBG    1201’, there is relatively little pollen which doesn't produce    viable seed (sterile) (FIG. 10).

TABLE 1 Statistical analysis of vegetative traits in March 2021 between‘DALBG 1201’, ‘Reveille’, and ‘Rebel Exeda’ tall fescue. Plant heightLeaf blade before stem Rhizome internode length§ Rhizome diameter§Length† Width† elongation‡ 1st 2nd 3rd 4th 4th internode 4th nodeCultivar cm mm cm mm DALBG 1201   8.90 a   3.28 b   17.78 a 11.74 15.7613.77 12.11   0.58 a   1.04 a Reveille   6.27 b   2.10 c   17.97 a 12.0912.39 10.59  9.96   0.32 b   0.70 b Rebel Exeda   8.49 a   3.71 a  16.16 b — — — — — — Fisher’s LSD¶  1.50  0.32  1.37 NS NS NS NS  0.10 0.14 C.V.# 22.80 12.62  9.52 20.82 29.38 31.97 43.20 23.78 18.26 †Bladeleaf length (cm) and width (mm) were measured from the first fullyexpanded leaves before stem elongation. ‡Plant height before stemelongation (cm) was measured from the four tallest leaves. §Rhizomeswere not available for Rebel Exeda so DALBG 1201 was only compared toReveille. Internode lengths and diameters were only measured fromrhizomes with a new shoot. ¶Four sample measurements were collected foreach replicate pot and trait for a total of 12 samples. If the ANOVA wasdetermined to be significant at the 0.05 probability level, means wereseparated using Fisher’s LSD. #Coefficients of variation were calculatedby dividing the root mean square error by the grand mean and multiplyingby 100.

TABLE 2 Statistical analysis of floral traits in March 2021 between‘DALBG 1201’, ‘Reveille’, and ‘Rebel Exeda’ tall fescue. AscendingFlorets culm Inflorescence Flag Flag Panicle Panicle Pedicel per Glumeinternode Culm length (plant leaf leaf Peduncle diameter length lengthspike length length† diameter‡ height)§ length¶ width¶ length# †† †† ‡‡§§ ¶¶ Cultivar cm mm cm cm mm cm cm cm mm no. mm DALBG 1201 13.39 a 0.62  34.75 c   2.37 b   2.26 b   5.75 b   2.40 a   5.18 b   5.07 a 3.92   4.42 b Reveille 11.75 ab  0.53  40.64 b   2.88 b   2.13 b  11.78 a   1.83 b   5.33 b   4.08 b  4.75   3.32 c Rebel Exeda 10.76 b 0.84  46.93 a   4.47 a   3.25 a   12.85 a   1.70 b   7.37 a   5.22 a 4.17   5.81 a Fisher’s LSD## 2.00 NS  3.94  0.70  0.38  1.81  0.31 1.22  0.81 NS  0.59 C.V. ††† 20.13 61.82 11.62 26.02 17.81 21.50 18.9224.53 20.33 28.57 15.70 †The ascending culm internode length (cm) wasmeasured between the nodes of the first and second leaves of the fourtallest inflorescences. ‡Culm diameter (mm) measured the thickness ofascending culm. §Inflorescence length or plant height were measured atfull maturity from the base of the plant to tip of the inflorescence.¶Flag leaf length (cm) and width (mm) were measured from the fourtallest inflorescences in each pot. #Peduncle length (cm) was measuredbetween the flag leaf node and base of the inflorescence. †† Paniclediameter (cm) and length (cm) were measured from the four tallestinflorescences. ‡‡ Pedicel length (mm) was measured between the node ofthe second branching spikelet and base of the first floret. §§ Thenumber of florets per spikelet were counted randomly from one spikeletfrom each of four inflorescences. ¶¶ Glume length (mm) was measuredbetween the base of a lower glume and tip of an upper glume. ##Foursample measurements were collected for each replicate pot and trait fora total of 12 samples. If the ANOVA was determined to be significant atthe 0.05 probability level, means were separated using Fisher’s LSD. †††Coefficients of variation were calculated by dividing the root meansquare error by the grand mean and multiplying by 100.

-   Establishment and turfgrass performance evaluation: 47 experimental    hybrids including ‘DALBG 1201’, along with five Texas bluegrass    ecotypes (‘TAES 5679’, 5681-5684), six Kentucky bluegrass genotypes    (‘H8G-J86’, ‘PTDF-22-B-2’, ‘H86-712’, ‘TAES 5701’, ‘TAES 5706’, and    ‘TAES 5709’), two commercial hybrid bluegrass checks (‘Reveille’,    ‘Thermal Blue Blaze’), and ‘Rebel Exeda’ tall fescue were assembled    for a multi-location test. Entries were planted under full sunlight    in a randomized complete block experimental design with three    replications in each of five test locations and were evaluated over    a period of 3 year from 2010 to 2012. Test sites were located in    Auburn, Ala., Dallas, Tex., Starkville, Miss., Raleigh, N.C., and    Knoxville, Tenn. For experimental hybrids, a 7.62-cm by 7.62-cm plug    was planted in a 0.61-m by 0.61-m plot during September to    October 2009. Commercial hybrid bluegrass cultivars were established    by seed, planted at a rate of 14.65 g m-2, and ‘Rebel Exeda’ was    seeded at 29.29 g m-2. Plots were irrigated to promote establishment    in Year 1 of the trial, with at least 2.54 cm of irrigation applied    weekly to supplement rainfall. Thereafter, irrigation was provided    to prevent dormancy or stress. After initial establishment, plots    were mowed at a 5.08 cm to 6.35 cm height. Nitrogen (N) was applied    at rate of 19.53 to 29.29 g m-2 each year in split doses once in    each fall, winter, and spring growing seasons. A weed management    protocol was implemented according to local weed pressure at each    test location. No preventative or curative pesticides were used    during the course of the study to control insect or disease    problems. Data for average monthly air temperature and precipitation    from 2010 to 2012 were collected from a local weather station at    each test location. Turfgrass performance data were collected on a    monthly basis from 2010 to 2012, but the frequency of data    collection varied by location. Traits included overall turfgrass    quality (1=poor; 9=ideal), seasonal color (1=straw brown; 9=dark    green), shoot density (1=poor; 9=maximum density), and leaf texture    (1=coarse; 9=fine). Summer turfgrass quality data were derived from    the turfgrass quality ratings for the months of June to September    (2010-2012) for each test location. Data for ‘DALBG 1201’ and the    three commercial checks are presented in Tables 3-7. All of the    datasets were analyzed using SAS 9.3 (SAS Institute, 2009). Means    were compared using Fisher's LSD at the a=0.05 probability level.    For each trait×location analysis, entries with means in the top    statistical group were followed by the letter a. Based on the    average air temperature and precipitation data for the months of    June through September each year (2010 to 2012), Dallas had the    warmest average temperature, followed by Starkville, Auburn,    Raleigh, and Knoxville. The Dallas location also had the least    amount of precipitation over the 3 year, followed by Auburn,    Raleigh, Knoxville, and Starkville.-   Traits and characteristics of ‘DALBG 1201’:    -   -   Turf quality.—The turfgrass quality for ‘DALBG 1201’ was            statistically superior to ‘Reveille’ and ‘Thermal Blue            Blaze’ in four test locations (Auburn, Ala., Starkville,            Miss., Raleigh, N.C., Dallas, Tex.), and was in the same            statistical group in Knoxville, Tenn. (Table 3). The            turfgrass quality of ‘DALBG 1201’ was statistically similar            to ‘Rebel Exeda’ at Auburn, Starkville, and Knoxville and            was superior in Dallas. When averaged across all locations,            the turfgrass quality of ‘DALBG 1201’ was statistically            superior than the commercial checks ‘Thermal Blue Blaze’,            ‘Reveille’, and ‘Rebel Exeda’. Summer turfgrass quality for            ‘DALBG 1201’ was superior to ‘Reveille’ in Auburn, Raleigh,            and Knoxville and was statistically similar in Starkville            and Dallas (Table 4). ‘DALBG 1201’ outperformed ‘Thermal            Blue Blaze’ in Raleigh, Knoxville, and Dallas and was            statistically similar in Auburn and Starkville. ‘DALBG 1201’            outperformed ‘Rebel Exeda’ in Knoxville and Dallas and            exhibited statistically similar summer turfgrass quality in            Auburn, Starkville, and Raleigh. The 3-yr average across all            locations showed that ‘DALBG 1201’ performed significantly            better than the commercial checks. The significantly            superior performance of ‘DALBG 1201’ in Auburn and Dallas,            two of the warmest and driest locations, suggests that            ‘DALBG 1201’ has improved summer stress tolerance. Improved            summer performance of ‘DALBG 1201’ likely results from it            being an F₁ hybrid from a cross between locally adapted            ecotypes of Texas bluegrass and Kentucky bluegrass collected            from Texas.        -   Seasonal color.—‘DALBG 1201’ was in the top statistical            group across all five test locations for seasonal color            (Table 5). With an average color rating of 7.3, ‘DALBG 1201’            was statistically darker green than ‘Reveille’ (average            rating of 6.2) and ‘Thermal Blue Blaze’ (average rating of            6.1) across all five test locations. Compared with ‘Rebel            Exeda’, the color rating of ‘DALBG 1201’ was in the same            statistical group at four out of five test locations except            at Auburn, where ‘DALBG 1201’ was statistically darker            green.        -   Shoot density.—Shoot density data were collected at four            locations (Table 6). Mean shoot density of ‘DALBG 1201’ was            significantly higher than ‘Reveille’ and ‘Thermal Blue            Blaze’ in Raleigh and Dallas. ‘DALBG 1201’ was statistically            similar to ‘Rebel Exeda’ in all locations. On average, the            shoot density rating of ‘DALBG 1201’ (7.1) was significantly            higher than that of ‘Reveille’ (6.1) and ‘Thermal Blue            Blaze’ (5.6) and was comparable to ‘Rebel Exeda’ (6.8).        -   Leaf texture.—With an average leaf texture rating of 6,5,            ‘DALBG 1201’ had a significantly finer leaf texture than            ‘Rebel Exeda’ (4.0) across all test locations (Table 7). The            leaf texture rating for ‘DALBG 1201’ was in the same            statistical group as ‘Reveille’ at all five test locations.            Compared with ‘Thermal Blue Blaze’, the leaf texture rating            for ‘DALBG 1201’ was in the same statistical group at four            locations except Dallas, where ‘DALBG 1201’ had a            significantly finer leaf texture (5.7). The leaf texture of            ‘DALBG 1201’, then, is comparable to the commercially            available hybrid bluegrass varieties included in the study            but significantly finer than the tall fescue check.        -   Disease susceptibility.—Rust (Puccinia spp.) was only            observed in Auburn, during the months of May (2010) and            April (2011), and Raleigh, during the months of April and            June (2012). ‘DALBG 1201’ and the commercial checks            exhibited no disease damage in 2010 and 2011 in Auburn. In            Raleigh, no rust was observed on ‘Rebel Exeda’. ‘DALBG 1201’            (7%), ‘Thermal Blue Blaze’ (7%), and ‘Reveille’ (5%) showed            minimal rust damage in Raleigh, N.C. (data not shown).        -   Genotype x environment stability analysis.—Stability was            defined as consistently superior performance of a genotype            across varying environments (poorest to best) based on the            performance of traits under consideration. Superior            performance in the poorest environments and higher levels of            stability (lower slope coefficient) indicates high stress            tolerance and wide adaption of a genotype across            environments, traits that are highly desirable when breeding            improved stress tolerant cultivars. Stability analysis of            turfgrass quality indicated that Dallas represented the            poorest environment and that Knoxville was the best.            Turfgrass quality ratings for ‘DALBG 1201’ were not only            higher in Dallas relative to all three commercial checks            (FIG. 1a ), but ‘DALBG 1201’ also had the lowest slope            coefficient of 0.698, indicating the highest stability            across locations. For shoot density, ‘DALBG 1201’            outperformed all three commercial checks under poorest            environments (Auburn), indicating its potential for stress            tolerance, and had the second highest stability across            locations next to ‘Rebel Exeda’ as indicated by the slope            coefficient of 1.064 (FIG. 1b ). For seasonal color,            although ‘DALBG 1201’ had highest cultivar mean across all            five locations and its slope indicated reasonable stability            (FIG. 1c ), its coefficient of determination (r2) was low,            suggesting that the linear regression model did not fit the            data. Nonlinearity has been shown to be an important tool in            analyzing genotype×environment interactions in other crops            and systems (Yang, 2014), and it appears that ‘DALBG 1201’            is following a nonlinear regression for the color response.            For leaf texture, all three hybrid bluegrasses (‘DALBG            1201’, ‘Reveille’, and ‘Thermal Blue Blaze’) outperformed            ‘Rebel Exeda’ when evaluated at the location with the            poorest environmental conditions (Dallas). ‘DALBG 1201’ had            the second-lowest slope coefficient of 0.967 next to            ‘Reveille’ (b=0.957) and was more stable across locations            relative to ‘Thermal Blue Blaze’ and ‘Rebel Exeda’ (FIG. 1d            ).

TABLE 3 Mean turfgrass quality for ‘DALBG 1201’ and three commercialchecks for five test locations. 1-9 Auburn, Starkville, Raleigh,Knoxville, Dallas, Entry AL MS NC TN TX Avg.‡ DALBG 1201 6.8a* 5.6a 6.3b8.0a 5.6a 6.5a Rebel Exeda§ 6.7a 5.4ab 6.8a 8.0a 4.2b 6.2b Reveille§5.7b 5.0bc 5.2c 7.9a 4.5b 5.7c Thermal Blue Blaze§ 6.0b 4.6c 4.9c 8.1a3.4c 5.4d LSD (0.05) 0.6 0.5 0.5 0.3 0.7 0.2 CV, %¶ 9.6 9.9 8.1 3.8 16.49.0 *Significant at the 0.05 probability level. † Scale of 1-9, where 1= poor, 9 = ideal, and 5 was the minimum acceptable. Mean representsturfgrass quality data for years 2010, 2011, and 2012 at each location.‡Average turfgrass quality of each entry across all locations from 2010to 2012. §Commercial checks included are ‘Rebel Exeda’ tall fescue and‘Reveille’ and ‘Thermal Blue Blaze’ hybrid bluegrasses. ¶CV (coefficientof variation) indicates the percentage variation of the mean in eachcolumn.

TABLE 4 Mean summer turfgrass quality ratings for ‘DALBG 1201’ and threecommercial checks for five test locations 1-9 Auburn, Starkville,Raleigh, Knoxville, Dallas, Entry AL MS NC TN TX Avg.‡ DALBG 1201 6.7a*5.0a 6.5a 8.6a 5.1a 6.1a Rebel Exeda§ 6.4a 5.0a 7.1a 8.0b 4.0b 5.9aReveille§ 5.7b 4.7a 5.1b 8.2b 4.5ab 5.3b Thermal Blue Blaze§ 6.1a 4.3a5.1b 8.1b 3.1c 5.0b LSD (0.05) 0.6 0.7 0.7 0.3 0.8 0.3 CV, %¶ 10.1 12.411.8 2.1 19.4 10.8 *Significant at the 0.05 probability level. † Scaleof 1-9, where 1 = poor, 9 = ideal, and 5 was the minimum acceptable.Mean represented turfgrass quality data for Auburn, AL (2010, 2011,2012), Dallas, TX (2010, 2011, 2012), Starkville, MS (2010, 2011),Raleigh, NC (2010, 2011, 2012), and Knoxville, TN (2010, 2011), from themonths June through September. Auburn data from 2010 and 2012 onlyincluded the months of June through August. Dallas data from 2010 onlyincluded the months of August and September. ‡Average turfgrass qualityof ‘DALBG 1201’ and three commercial checks across all locations from2010 to 2012. §Commercial checks included are ‘Rebel Exeda’ tall fescueand ‘Reveille’ and ‘Thermal Blue Blaze’ hybrid bluegrasses. CV(coefficient of variation) indicates the percentage variation of themean in each column.

TABLE 5 Mean seasonal color for ‘DALBG 1201’ and three commercial checksfor five test locations. 1-9 Auburn, Starkville, Raleigh, Knoxville,Dallas, Entry AL MS NC TN TX Avg‡ DALBG 1201 8.1a* 6.5a 7.2a 7.5a 7.0a7.3a Rebel Exeda¶ 7.2b 6.8a 7.3a 7.3ab 7.0a 7.1a Reveille¶ 6.4c 6.0b6.1b 6.5c 6.1b 6.2b Thermal Blue Blaze¶ 6.2c 5.9b 6.0b 6.8bc 5.7b 6.1bLSD (0.05) 0.6 0.4 0.5 0.5 0.5 0.3 CV, %# 11.3 6.6 9.2 7.5 10.5 9.3*Significant at the 0.05 probability level. † Scale of 1-9, where 1 =straw brown, 9 = dark green. Mean represented color data from 2010 to2012 at each location. Starkville, MS data was pre- seined for 2010 and2011. § Average seasonal color across all locations from 2010 to 2012.¶Commercial checks included are ‘Rebel Exeda’ tall fescue, and‘Reveille’ and ‘Thermal Blue Blaze’ hybrid bluegrasses. #CV (coefficientof variation) indicates the percentage variation of the mean in eachcolumn.

TABLE 6 Mean shoot density for ‘DALBG 1201 ’ and three commercial checksfor four test locations. 1-9 Auburn, Starkville, Raleigh, Dallas, EntryAL MS NC TX Avg.‡ DALBG 1201 3.7a 8.5a 8.2a 6.7a 7.1a Rebel Exeda¶ 3.0a8.5a 8.2a 5.9ab 6.8a Reveille¶ 2.7a 8.3a 6.2b 5.7b 6.1b Thermal BlueBlaze¶ 2.3a 8.5a 5.8b 4.6c 5.6c LSD (0.05) 1.3 0.9 1.1 0.8 0.5 CV, %#25.0 9.6 13.9 13.9 13.5 * Significant at, the 0.05 probability level.‡Scale of 1-9, where 9 = maximum density. Mean represented density datafrom Auburn, AL (2010), Dallas, TX (2010, 2011, 2012), Starkville, MS(2010, 2011), and Raleigh, NC (2011, 2012), § Average seasonal color andshoot density across all locations from 2010 to 2012. ¶Commercial checksincluded are ‘Rebel Exeda’ tall fescue, and ‘Reveille’ and ‘Thermal BlueBlaze’ hybrid bluegrasses. #CV (coefficient of variation) indicates thepercentage variation of the mean in each column.

TABLE 7 Mean leaf texture for ‘DALBG 1201’ and three commercial checksat five test locations. 1-9 Auburn, Starkville, Raleigh, Knoxville,Dallas Entry AL MS NC TN TX Avg.‡ DALBG 1201 6.2a* 5.8a 7.0a 8.7a 5.7a6.5a Rebel Exeda¶ 3.0b 4.3b 5.0b 7.0b 2.3c 4.0b Reveille¶ 6.0a 5.5a 7.0a8.3a 5.7a 6.3a Thermal Blue Blaze¶ 6.6a 5.8a 7.0a 8.3a 4.0b 6.3a LSD(0.05) 0.9 0.6 0.3 1.3 0.9 0.4 CV, %# 16.2 9.3 13.0 8.8 11.3 11.6*Significant at the 0.05 probability level. † Scale of 1-9, where 1 =coarse, 9 = fine. Means represented data from Auburn, AL (2010, 2011,2012), Dallas, TX (2012), Starkville, MS (2010, 2011), Raleigh, NC(2012), and Knoxville, TN (2011). ‡Average leaf texture across alllocations from 2010 to 2012. § Commercial checks included are ‘RebelExeda’ tall fescue, and ‘Reveille’ and ‘Thermal Blue Blaze’ hybridbluegrasses. ¶CV (coefficient of variation) indicates the percentagevariation of the mean in each column,

What is claimed is:
 1. A new and distinct interspecific hybrid varietyof bluegrass named ‘DALBG 1201’ as shown and described herein.